The wood tick that will give my dad Rocky Mountain Fever is born in a bed of blanket flower and yucca. It is deposited by an engorged female, one of nearly four thousand eggs. As soon as it detects atmospheric carbon—fresh air—on its dorsal shield, its red-brown body emerges into the world.

It is microscopic and as pestilent as a mosquito. Upon completing its larval life cycle, it enters its nymph stage and lights out, searching for a host. It leaves behind the dead flesh of a small mammal and drops to the forest floor, where it molts, hardens its shell, and grows two more legs. It will re-emerge from the undergrowth in its final phase, an adult hungry for one more mammal.

This is the spring my father comes to visit me out west, where I have managed, somehow, to finish college at a small state school in Montana.

Blood is a tick’s seasons, its ages and its episodes. It will feed only three times in its two-year life before it dies, each time molting into yet another version of itself.

I envy how the tick measures its life in such a singular and deliberate way. I will measure mine in messy, often overlapping interludes that may or may not include marriage, promotions, divorce, layoffs, sickness, and injuries. The tick’s life moves forward in distinctive stages, leaving one stage behind before it leaps into another, until it latches onto my dad’s leg.

He finds it on the morning of my graduation, just before he is taken away in an ambulance, hot with fever and as dehydrated as a California raisin.

*

My first memory is of Dad. I’m hovering. Water is in my eyes and sun refracts through its beads like bike spokes. A moment in the air: I quiver, I clench, and I crack into the water. I come up laughing. I hold him only long enough to catch my breath, and then I beg him to toss me again. As far away as possible.

“Stay within eyesight,” my mom always said when we’d go to the beach. Even in the inland lakes of the Midwest, my parents understood the nature of tide and current. Of being carried away. That they could save me, so long as they could see me.

I took delight in the wide arc of flight between my dad’s arms and the murky, dark lake water. But the real thrill was the moment I surfaced and found myself far out of his reach, several arms’ lengths from his warm barrel chest. The distance between us was possibility. Just a few feet from my father, I could only float where he was tall enough to stand, and the rippling water between us coalesced into the depths of the rest of the lake. Treading water, I could feel for the first time that I was part of a larger world beyond both myself and my parents, a cosmos even, in which the distance between us was a fraction of the distance I could one day travel.

But then–I’d paddle back in a terrified frenzy. It would be years before all that space represented anything but fear. I didn’t want to completely let go.

I spent most of my time in the backyard of my childhood home, on a modest plot in a modest neighborhood north of Detroit. The half-acre lot was a perfect square hemmed by ponderosa pine, white fir, wrought iron, and raspberry bushes. Sometimes, I talked to the girl on the other side of the fence. Our backyards were separated by a gate. Her mother was an angry woman who wouldn’t allow her daughter too close to the edge of her yard. Through the raspberry bushes I heard sounds of bottles smashing on walls.

That side of the fence became a frontier. I was too young to understand infatuation or desire, but the loneliness and longing of that girl reflected my own sheltered curiosity back to me. I fantasized about jumping the gate and running away with her; the distance was as forbidding as it was as alluring. Open spaces receding like a hand waving goodbye.

*

My first foray out west was on a Greyhound with a group of teenagers, just after I turned fifteen. Most of them begged their parents to sign them up—to pack them extra socks, hiking boots, travel toothpaste and pre-addressed stationery and send them away—but mine had to make me go. They bought me a duffel bag and a backpack, gently but insistently encouraging me to leave.

The Rocky Mountain West is alien in its infinite space to someone from the carefully-plotted Midwest. From the tops of even its smallest foothills, distance is extended to the curvature of the Earth and the human scale evaporates.

As our bus rattled up the first winding roads of the Rockies, I felt my old fascination with distance return to match the scope of these new, ever-widening vistas. I couldn’t look at a range of mountains disappearing into blue-and-purple swells without an insatiable curiosity of what it must be like on each of the next ridgelines.

*

The Centers for Disease Control identify seven species of dangerous tick. The tick that will lie in wait for me to move out west is a Rocky Mountain Dog Tick. It doesn’t know that, as it evolves from larva to nymph, it carries pathogens strong enough to kill even a full-grown adult male. It knows only that it is hungry, and that the blood of voles and chipmunks will soon no longer be enough. It only needs three days to feed to retrieve the full nutrients of its meal: a poor vole. Once it detaches, satiated, it will fall into a biological diapause as the platelets and the minerals in mammal blood coagulate in its own system, so that it can come back grown, ready, and strong enough to find an even bigger victim.

To itself, it is just the logical conclusion of its own evolution. To everything else, it is a disease.

*

Somewhere along the way up Half Dome Mountain in the country’s fourth-oldest national park, our group found a camp a few hundred paces uphill from the edge of Yosemite Falls: a translucent thread shimmering against the upland California canyonland. We pitched camp hastily and slept intermittently, anxious from the unfamiliar energy haunting us in the total silence and dark that only a foreign wilderness can contain. The moon looks different in every new valley. This fresh information—the Earth as an infinite geography that expands into both constellation and bedrock—unsettled me. Until then, I had been convinced that everywhere was the same; that every mother drove a Ford Windstar minivan and said I love you even when they were mad; that everyone I will ever love I’ve already met. But beyond the steep, sharp edge of the eight-thousand-foot Half Dome Mountain was an unknown distance into unknown dark I hadn’t known existed.

Some of the other Midwestern kids were unfazed by the abyss. But during the hike up, on stony and ceaseless switchbacks, I could do nothing but lose my footing for staring slack-jawed at the array of summits. They went on forever. A geologist would tell you that they rolled logically toward the glacial moraine, now eroded into the silt at Tuolomne Meadows, where the last ice age began its retreat. A high-altitude series of swollen mounds and wildflowers, the cradle of the Sierra Nevada is only a few miles upvalley from Half Dome. But having never seen further than the tip of my mother’s minivan, my notion of distance had always been measured in feet—careful suburban grids where you couldn’t get lost even blindfolded. But here was a valley so giant that as it dissipated into sky, it reached back an ice age.

The tents had been arranged haphazardly in a semi-circle around an aspen tree, and we woke thirsty, hungry, and desperate for reassurance that the world below, on the valley floor, still existed. The other campers packed up enthusiastically to leave for our next destination. I, alone, was slow to pack up my bedroll.

On our aching descent down to the stream to fill our water bottles, a camper lost her footing on a scree slope and tumbled. She collected a few scrapes and bruises, but her ankle was twisted enough that she couldn’t walk out. She iced her tendons in a natural spring, and I took my pack off to wait for instructions from the guide.

Yosemite Falls pools just before it tumbles off into oblivion. You can sit in the dammed-up water at the very edge without concern. The distance is all potential. The rock was warm, and I napped in the alpine grass and let myself imagine what the top of the valley looks like. Tuolomne Meadows. The complex web of streams and gullies that cascade out of the uplands to form Yosemite Valley is an ancient secret you can only see from the sky. I wanted to stay there—if not in this exact warm pool at the edge of the earth, then at least among spots like this, in between a million of these moments.

By the time I was back in Detroit, distance had transformed from a physical revelation to a psychic need. I went home, but I never really came back.

*

My dad’s first memory is clear: he’s lying in the back of someone’s car, face-up, staring skyward out the window. Streetlights blow by like stars sucked into black holes. The car pulls up into the long, single-track driveway to the detached garage behind a brick bungalow in Detroit’s Corktown.

He’s home, but he’s never seen this place before. He’s never seen these people before.

His adoptive mother, Hazel, keeps a double-barrel shotgun in the armoire in the living room. His adoptive father is gone before he turns ten. He will archive a million more memories, still, entire movements of his life that pass by without much notice, until he brings his own firstborn son home.

In short order, he learns to play guitar, how to box. He plays high school football; he goes away to college; his draft number is called, but the war ends in time; he goes back to college, joins the crew of a Great Lakes freighter, joins a folk band in California, returns home, meets my mom, has my older brother, has me. Hazel dies—and then my dad watches my brother and me rise up and out of adolescence like rockets shedding superfluous parts, until there is nothing left but hot centers screaming toward the sun.

My father hardly ever talks about growing up with Hazel. He doesn’t talk about how, for most of his life, the highest peaks he’d seen were the swells on the Great Lakes when he worked the deck of a freighter. He saw a man die after stumbling into an aluminum haul line quivering in a storm. A group of white deckhands killed a Mexican cook on his boat when they discovered the man had stolen a camera. It was later that he treated himself to his own private distances—he played in a folk act in California for a brief summer, and he bought himself a motorcycle in Ypsilanti, Michigan. But those were, ultimately, quick dalliances, and by the time my brother and I came along, my father had settled into the quiet grid of streets I would later throw back into his face for just the comfort and coziness of life he built for us.

Of all my dad’s sacrifices for my brother and me, the greatest is that he’ll never let us know how much he’s sacrificed, for fear it will make us want to stay.

Instead, he allows us—encourages us—to detach. In exchange, he asks only that we never question what he had to do to provide us this luxury.

By the time my brother and I are off to college, we are on trajectories Dad could only ever dream of.

What hurts him is not that we’ve fled the Midwest for other places and opportunities–it’s that we do it with impunity. We do it as people who’ve never had to wonder whether or not there will be a place for them, should they return. Why look back when you know exactly what you’ll find when you do?

*

Missoula, Montana, where I attend university, is 1600 miles away from the careful grid of my suburban Detroit neighborhood. It is an old train-stop town, dug into the clay of the Bitterroot Valley, and it rests in the balance between forest fire and excruciating cold. My parents make the trip regularly. They stock my refrigerator, and sometimes my dad sneaks a hundred dollars in cash onto my pillow before getting back on the plane. They come to congratulate me—indeed, to support me—in successfully distancing myself from them. In this, they are genuine. They forgive me my petulance. They are truly proud that I’ve found some independence and confidence. If there is anything they cannot forgive, it is nature, because it is exactly and only natural that the end result of their successful parenting is a child who will want to leave.

Sometimes my mother muses about what would’ve happened if she never sent me out west on that bus trip. I remember the girl in the adjacent backyard, her miserable mother yelling for her to stay close. What would have happened, I wonder. What wouldn’t have happened?

On the eve of my graduation, my parents take a hike through the mountains near campus. The wood tick waits along the trail. Later, my dad takes me to the Silver Dollar Bar just outside Missoula, where the dust of the planes has piled up against the Rocky Mountain Front. My hometown hockey team, the Detroit Red Wings, is playing San Jose. Dad asks the bartender to find the game on one of the TVs, and he buys me a shot of tequila every time the Wings score a goal. I try to stomach both my disinterest in hockey and my queasiness at tequila. There’s a distance he’s trying to bridge—my hometown and my new town, his suburb and my mountains—and I let him.

My dad raises a glass.

“To my son,” he says.

“To me,” I agree.

We drink half a bottle of Patrón Silver together. It’s what I remember most now: not the small departmental ceremony the next day, or that the Red Wings were flounced.

The tick is an adult now, too. It had woken from its dormancy, and just as it began to look around for its final meal, my father, who would follow me to any distance, arrived in the Bitterroot Valley.

And now, though one of us will die in the next twelve hours, my dad and I celebrate my own impending transformation.

*

It seems impossible that the wood tick could know its own life is winding down, that it will complete its life cycle when it attaches and releases from one more mammal. But nymph ticks that attach for the final meals ushering them toward adulthood often remain latched long past their biological need. They hang on for nine, ten, eleven days, gorging and desperate. This is when humans and dogs and cats get sick—the length of time of attachment directly correlates to the likelihood of contracting Rocky Mountain Fever or Lyme Disease.

Can we blame the tick for hanging on so long? It must know that letting go means the end.

A teenager from Detroit discovers he loves the outdoors and moves out west. He drags his parents along simply because he knows they’ll come.

*

My mom arrived at my graduation ceremony alone, having left my father sick at the hotel. Later, she tells me that she’d been terrified to leave him alone, but that she wouldn’t have forgiven herself for missing my graduation. While I simply stroll across a folding stage at a forgettable departmental ceremony, his fever is hitting 104 degrees.

He hallucinates, sweats, vomits, and sleeps in cycles until my mom can return to help him put on sweatpants so that they can get to the emergency room. She notices, then, a small, black mark embedded in the flesh of his leg just above the cuff of his briefs.

*

Two humans saunter down a forest path, a man in front of a woman. They keep their gaze above and ahead of themselves. Horizons, mountain summits, sunsets: what humans have always found beautiful, they’ve found in distances. This pair is no different. They wonder at the river beneath them, the horseshoe of jagged crags at the tip of the valley.

The man—who’s here only to see his son off, again—brushes a web of nettles, and the tick deftly transfers itself to the skin and bites down.